Method and apparatus for completing wells



March 2 1943. L A BERMNGHAM, JR 2,312,862

METHOD AND APPARATUS Foa GOMPLETING WELLS Filed Jan. 26, 1940 FIG. 2

" FIG. l-

JAMES A. BERMINGHAM JR. NVENTOR /e//J `BY IQ/21, HIS ATTORN YS PatentedMar. 2, 1943 METHOD AND APPARATUS FOR n COMPLETING WELLS James A.Bermingham, Jr., Long Beach, Calif., as-

sig'nor, by mesne assignments, Company, New York, N. Y., a

` Delaware to The Texas corporation of Application January 26, 1940,Serial N0. 315,668

(Cl. 16S-1) 4 Claims.

This invention relates to methods and apparatus for completing wellsand, more particularly, to the completion of a well in which a pack ofgravel or other granularmaterial is placed around a perforated liner orscreen in the well cavity.

The principal object of the invention is to provide a method and meanswhereby a liner Inay be used which is larger in diameter than couldnormally be used with a given size of casing while still providingsufficient space around the liner to accommodate a suitable gravel pack.Another object is to provide means for suspending the liner from thewell casing after the gravelv has been placed in the well.

It is more or less common in the graveling of a well to circulate thegravel or other granular material with a carrier iiuid downwardly in thespace between the casing and a tubing string, the gravel remainingaround a screen or perforated liner at the bottom of the hole and thecarrier uid passing into the liner or screen and upwardly to the surfacethrough the tubing. It is usually necessary to use a, liner considerablysmaller in diameter than the casing so as to provide sumcient annularspace around the upper portion of the liner through which the gravel maypass downwardly to the well cavity. Moreover, the gravel usually extendsupwardly in the annular space between the lower portion of the casingand the upper portion of the liner since it is frequently not knownexactly when the right amount of gravel has been placed to reach just tothe top of the cavity. Obviously, if a liner were used but slightlysmaller in diameter than the casting, it might still be possible to runthe liner down through thev casing but there would be little,

if any, space left between the liner and the casing to provide passagefor the gravel. It is naturally an advantage to use as large aperforated liner or screen as possible since with a large diameter linerthere is a larger peripheral area and there are more perforations perfoot. Furthermore, the larger the liner, the larger the pump which maybe used.

In accordance with the invention a method has been provided whichconsists of attaching to the lower end of the main casing one or morejoints of casing larger in diameter than that used in the main casingstring so as to provide a comparatively large annular clearance spacebetween the inside surfacek of the larger section of casing and theoutside of the liner or screen, thereby permitting a larger size lineror screen to be used for a given size of the main casing. A liner orscreen but slightly smaller in diameter than the inside diameter of themain casing is run into the well cavity vand the upper part of the linerwill extend up'within the section of larger casing. Thus, in this mannerthe liner used may be nearly as large in diameter as the main casingstring, while at the same time sulcient annular space will be providedaround the upper portion of the liner to allow passage of the gravel andto accommodate the upper portion'of the gravel pack. Means are alsoprovided whereby, after the tubing string is Withdrawn from the bore theliner may be hung or suspended from the main casing while the lower orscreen portion of the liner remains surrounded by gravel in the wellcavity.

For a better description of the invention reference may be had to theaccompanying drawing in which Figure 1 is a vertical sectional viewthrough the lowerl portion of the well before the gravel is placed,while f Figure 2 is a sectional view somewhat similar to Figure 1 butshowing the method of suspending the liner after the gravel has beenpositioned.

With reference to the drawing. the lower end of a hole or bore I0 hasbeen shown as having been drilled through a producing formation I2. Inorder to describe the invention more clearly certain typical dimensionswill be given, although these dimensions do not, of course, form a partof the invention. The portion of the hole ,III shown in the upper partof Figure 1 may be, say, 12% inches in diameter. After the hole has beendrilled and the desired location of the setting point of the casing hasbeen determined a portion vI4 of the hole is then underreamed or scrapedto a diameter of, say, 151/2 inches and this underreamed portion mayextend for a suitable distance such as feet above the point I6 at whichthe lower end of the casing is to be set. Starting about 5 feet belowthe setting point I6 of the casing hole is then underreamed to adiameter of 19 in es and this second underreamed portion I8 will extendto the bottom of the hole, i. e., through the producing formation I2.

After the hole I0 with the two underreamed or stepped portions I4 and I8has been prepared,

a casing string 2li of joints of 8%" casing will beV made up in theusual manner with tlfe exception that a 40 foot joint 22 of 9% inchcasing will be suitably secured on the bottom of the main or 8% inchstring. A oat collar (not shown) could be inserted in the stringdirectly above the junction of the 8% inch and 9% inch sections. The 9%inch casing section 22 would have a clearance of 1.31 inches in the 12%inch hole and no unusual diiliculty should arise in running the stringinto the hole. v

It will be observed with reference to Figure 1 that the string of casingis positioned in the hole with the bottom of the larger section 22 atthe setting point I6 and the enlarged casing section 22 extendingupwardly within the underreamed hole portion I4. The string of casing isthen cemented in the hole in any suitable manner, a portion of thecement being shown at 24. After the cement has set suflciently thecasing string will preferably be cleaned out thoroughly. If desired, thecasing string can be set prior to the operation of underreaming thelower portion I8 of the hole.

A liner 26 having a lower perforated portion or screen 28 and having anexternal diameter of, say, 65/8 inches is then run into the hole on astring of tubing 30. Resilient casing guides 32 are preferably securedto the upper portion of the liner before the latter is run in the holeand these guides will serve tocenter the top of the liner within thelarger section of casing 22. It will be observed that the width of theannular space between the 6% inch liner and the 9% inch casing is 1.05inches, which provides sufcient clearance for the passage of gravel inthe gravel packing operation. The lower end of the liner or screen maybe provided with a transverse plate 34 which will engage the formationat the bottom of the hole to prevent rotation of the liner after it hasvbeen positioned.

In order to secure the liner 26 to the tubing 30 during the operation ofrunning the liner into the hole, the lower end of the tubing string maybe provided with left hand threads 36 adapted to be threaded into a bossformed on a plate 38 secured as by welding to the inside of the liner26. The plate 38- is provided with a. center opening in alignment withthe tubing 30. If desired, a portion of the screen 28 below the plate 38may be previously lled with a quantity of gravel 40 held in place bymeans of a slotted or perforated plate 42.

In order to center the upper end of the liner 26 around the tubing 30and to prevent gravel, when passing downwardly through the casing,

from entering the upper end of the liner, a closure member 44 is securedas by welding to the tubing 30 and is provided with a downwardlyextending interior boss portion 46 adapted to fit within the upper endof the liner. The method of securing the liner 26 to the tubing 30 bymeans of the threaded section 36 and the provision of the closure member44 does not form a part of this invention, and are thoroughly describedand illustrated in the Patent Number 2,198,573, granted April 23, 1940,to E. L. Davis, H. S. Cole, Jr.. W. E. Larson and N. C. Wells.

After the liner has been placed in the hole in the manner illustrated inFigure. 1, a quantity of granular material such as gravel 48 iscirculated into the hole through the space between the casing and theliner 30. The gravel may be circulated into the hole by means of acarrier liquid such as oil or mud, the carrier liquid entering the lowerportion oi the screen 28 below the plate 38 and passing upwardly to thesurface through the opening in the plate 38 and the tubing 30. Althoughthis is the preferred method of placing the gravel in the hole, othermethods may be used without departing from the scope of the invention.

In Figure 2 the gravel 48 is shown filling the annular space in theunderreamed hole portion I8 and suflicient gravel will be used so thatit will extend upwardly in the annular space between the casing section22 and the upper portion of the liner 26. After the gravel has beenplaced the tubing 3l) is rotated so as to unscrew the connection 36,after which the tubing string can be withdrawn from the hole. A joint of6% inch casing or other pipe 58 having a slip type casing bowl 52 on thebottom is then run into the hole on drill pipe or tubing.

After the casing bowl has engaged and sur-V rounded the upper end of theliner 26, the liner is preferably pulled upwardly one or two feet so asto pack off the space between the inside of the bowl 52 and the upperend of the liner 26. The liner is then hung in tension from the casing20 by means of any suitable type of liner hanger 54. The drill pipe ortubing will then be removed from the casing section 50 in the usualmanner and when this operation has been completed, the well will beready to be placed on production.

It will be observed that with the method of completing a well such ashas been described, a liner can be used which is considerably largerthan could otherwise be used within a given size hole and casing. Thestepped or enlarged casing section 22 will provide sufcient annularspace for the gravel to extend upwardly around the upper portion of theliner 26.

As has been pointed out hereinbefore, although dimensions have beengiven for the sizes of the main hole IIJ, the enlarged portions I4 andI8, the main casing 20, the casing section 22 and the liner 26, thesehave been given for purposes of illustration only and may be consideredto illustrate one example or installation such as may be made incarrying out the invention. Other dimensions may be used, the principalpoint to be borne in mind being that the liner mustnaturally be smallerin diameter than the inside diameter` of the main casing, but onlysufficiently smaller so that the liner can be run freely through thecasing.

Obviously many modifications and variations of the invention as beforeset forth may be made without departing fromthe spirit andscope thereof,and therefore only such limitations should be imposed as are indicatedby the appended claims.

I claim:

1. A method of completing a well having a well bore extending into aproducing formation, which comprises underreaming a portion of the boreabove the producing formation to form a chamber, underreaming anotherportion of said bore to form a cavity below said chamber, the diameterof said cavity being greater than that of said chamber, placing in thebore a liner-screen assembly slightly smaller in diameter than the mainbore and with the lower or screen portion of the assembly in said cavityand the upper or liner portion within said chamber, the diameter of saidliner-screen being only suflicientlysmaller than the diameter of themain bore to permit lowering of the liner through said main bore, andplacing a quantity of granular material around said linerscreen assemblywithin said cavity and said chamber.

2. In a bottom hole assembly for a well bore provided with a casing andan enlarged cavity in a producing formation, a casing section larger indiameter than said first mentioned casing and depending therefrom to thetop of said cavity, and

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a perforated liner within said cavity and extending up within saidenlarged casing section, said t liner being but slightly smaller indiameter than the first mentioned casing.

3. A bottom hole assembly for a well bore having an enlarged cavity in aproducing formation and a chamber above the cavity, the chamber beixig,a liner-screenassembly positioned ing section, and the arrangement beingvsuch that space is provided around said assembly for accommodatinggranular material both within said cavity and between the upperportionof the assembly and said casing section. v

4. In a bore hole assembly for a well bore provided with a casing and anenlarged cavity in a producing formation, a casing section larger indiameter than said rst mentioned casing and depending therefromsubstantially to the top of said cavity, a perforated liner Within saidcavity and extending up within said enlarged'casing section, said linerbeing but slightly smaller in di# ameter than the rst mentioned casing,and

' means for sealing the space between the upper end of the liner andsaid first mentioned casing.

JAMES A; BERMINGHAM, Jn.

